The present invention is directed to RF transmitters and, more particularly, to monitoring and recording the fault status of various components of such a transmitter.
RF transmitters include AM, FM and TV transmitters and such transmitters typically include a group of RF amplifiers, power supplies with a plurality of components that may fail during operation. Consequently, it is important to monitor these components to determine the fault status thereof as being either active or inactive (fault condition or a no-fault condition). The components to be monitored frequently include a plurality of amplifiers each of which may have an over current fault status condition, or interlocks which may have a fault status in the event of an open door condition. Also, events should be monitored, such as whether an interlock fail safe is open or whether the transmitter ON push button has been pressed. In addition to the fault and the event conditions noted above it may be desirable to monitor various signals, such as analog signals to determine whether they are of a value below or above certain threshold values. The foregoing and other components, events and signal conditions may need to be monitored.
It is desirable that the monitoring of the above be accompanied by recording (or logging) to provide a record or xe2x80x9cfault logxe2x80x9d that contains important information, such as fault type (fault description), fault status, fault occurred time, and fault-cleared time. This monitoring and recording should take place periodically or iteratively and the fault log should be accessible to an operator as by providing a display or a printed copy.
The present invention provides for monitoring and recording the fault status of various components of an RF transmitter in real time. The apparatus includes a plurality of ports that each receive an indication of an active or inactive fault status from an associated one of a plurality of monitored components. A multi-bit fault status structure is provided with each bit being associated with one of the monitored components. Each bit has a binary value representative of either an active fault status or an inactive fault status of the associated one of the monitored components. A micro-controller is programmed in such a manner that it determines whether any of the fault status indications have been changed from an inactive status to an active status and if so, then for each monitored component, it sets the corresponding bit in the fault status structure to an active fault indication. If not, it resets the corresponding bit in the fault status structure to an inactive fault indication. The micro-controller is also programmed in such a manner that for each iteration it provides a fault log.
In accordance with another aspect of the present invention, a plurality of event ports are provided each for receiving an active or inactive event status from associated one of a plurality of monitored events taking place in the transmitter. A multi-bit event status structure is provided with each bit being associated with one of the monitored events. Each bit has a binary value representative of either an active event status or an inactive event status of the associated one of the monitored events. A micro-controller is programmed so that it determines whether any of the event status indications have been changed from being an inactive status to an active status, and if so, it sets the corresponding bit in the event status structure. If not, it resets the corresponding bit in the event status structure. The micro-controller is further programmed to provide an event log. The log is a record of events including, for example, the event type, the present status of the event as being active or inactive, the real time of event occurrence, and the real time that the event occurrence was cleared, if cleared.
In accordance with a still further aspect of the present invention a plurality of analog signal ports are provided that each receive an analog signal. A multi-bit fault status structure is provided with each bit being associated with one of the monitored signals and having a binary value representative of either an active fault status or inactive fault status of the associated one of the monitored signals. A micro-controller is programmed so that it determines whether any of the analog signals exceeds a threshold for that signal and if so, it sets the corresponding bit in the analog status structure to an active fault indication. The micro-controller is further programmed so that it provides an analog system fault log. The fault log contains, for example, the fault type, present status as being active or inactive, the real time of fault occurrence and the real time that the fault was cleared, if it was cleared.
In accordance with a still further aspect of the present invention, access is provided to the fault log as with a display device coupled to the micro-controller for providing video display of the fault log on the screen thereof or by means of a PC terminal coupled to the microcomputer and having a video display. The fault log display obtained from the microcomputer includes the fault sequence number, the fault type, the present status of the component, event or analog signal, the time of occurrence and the fault clearing time.